Apparatus for carbonizing carbonaceous material



March 2, 1965 J. A. FAGNANT 7 APPARATUS FOR CARBONI ZING CARBONACEOUS MATERIAL Filed June 27, 1961 s Sheets-Sheet 1.

47) INVENTOR.

ATTORNEYS March 2, 1965 J- A. FAGNANT 3,171,795 APPARATUS FOR CARBONIZING CARBONACEQUS' MATERIAL Filed June 27, 1961 s Sheets-Sheet 2 Jalmiflgm BY ATTORNEYS March 2, 1965 J. A. FAGNANT 3,171,795

APPARATUS FOR CARBONIZING CARBONACEOUS MATERIAL Filed June 27, 1961 3 Sheets-Sheet 3 INVENTOR f 69 2a 7/? WJ United States Patent 3,171,795 APPARATUS FOR CARBONIZING QARBONACEOUS MATERIAL John A. Fagnant, Kemmerer, Wyn, assignor to The Kemmerer Coal Company, Frontier, Wyo., a corporation of Wyoming Filed June 27, 1961, Ser. No. 122,375 13 Claims. (Cl. 202-129) This invention relates to chemical reaction apparatus and methods and is directed particularly to an improved structure and method of operating the same for the production of fuel gas, tar vapor and a carbonaceous solid residue or char.

A broad primary object of the present invention is to provide a new and novel method and apparatus for continuously carrying out endothermic chemical reactions involving a solid material having gas forming and liquifiable constituents and a gaseous substance.

Heretofore, in the fuel converting art, large reaction vessels requiring heat transfer at high temperatures have been made of refractory fire brick or high temperature alloy metals.

The refractory brick settings have low thermal conductivity and, therefore, transmit heat relatively slowly compared with the heat transfer rate through metals. In the use of metallic reaction vessels, there is a definite maxi mum temperature limit which restricts the flexibility of the process.

A further object of the present invention, in the light of the foregoing, is to provide an improved apparatus constructed in a novel manner and employing therein a material in the construction thereof by means of which the restrictions and problems associated with present types of apparatus are definitely overcome.

Another object of the invention is to provide, in a manner as hereinafter set forth, a reaction apparatus embodying an improved oven design in which the temperature limits which may be attained lie high above the maximum temperature limits obtainable in metallic reaction vessels.

A further and more specific object of the present invention is to provide a new and novel type of oven structure wherein the raw material under treatment is caused to move gravitationally at a desired rate over sloping surfaces and wherein means is provided for supplying heat to the raw material by the burning of gaseous vapors directly above the sloping bed of material.

A still further object of the invention is to provide a new and novel refractory oven structure, in the manner hereinafter set forth, wherein there are provided sloping surfaces formed of material having a high degree of thermal conductivity so that there is no critical temperature limit to the process carried out in the oven and the improved good heat transfer through such sloping surface allows for uniform carbonization to take place through the layer of material on top of such surface.

More specifically the invention has for an important object to provide such material supporting and heat transfer surfaces in the form of silicon carbide slabs.

Other objects of the present invention are to provide a structure for the production of low volatile char for chemical and metallurgical operations; to provide a suitable combustion system with flexible controls whereby to achieve the reaction desired without the formation of coke deposits caused by cracking or dissocation of hydrocarbon materials; to provide a method and apparatus for handling all non-caking, non-agglomerating or noncoking materials and in addition for handling caking, agglomerating and coking materials by the process of recycling a part of the finished product; to provide an ap- 3,1?1 ,795 Patented Mar. 2, 1965 paratus for the production of smokeless fuels from carbonaceous materials.

The invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawings forming a part of this specification with the understanding, however, that the invention is not confined to a strict conformity with the showing of the drawings but may be changed or modified so long as such changes or modifications mark no material departure from the salient features of the invention as defined by the appended claims.

In the drawings:

FIG. 1 is a view in perspective of an apparatus constructed in accordance with the present invention.

FIG. 2 is a sectional view in a vertical plane taken approximately on the line 2-2 of FIG. 1.

FIG. 3 is a sectional view taken approximately on the line 33 of FIG. 2.

FIG. 4 is a sectional view taken approximately on the line 44' of FIG. 3.

FIG. 5 is a sectional view taken approximately on the line 55 of FIG. 3.

FIG. 6 is a detail view illustrating a means for ad justing the degree of throw of the apparatus for moving the char from the receiving table onto conveyors.

FIG. 7 is a vertical section taken through a modified construction in a plane corresponding to the plane of section for the construction shown in FIG. 2 and illustrating certain modified features of the FIG. 2 construction.

FIG. 8 is a fragmentary sectional detail on an enlarged scale illustrating a valved air admission pipe.

The apparatus hereinafter more particularly described provides for the carrying out of an endothermic chemical reaction process involving a solid material and a gaseous or vaporous substance and in the operation of such apparatus the solid material is passed into an oven through a feed slot onto the surface of a sloping or an inclined wall formed of material having a high degree of thermal conductivity. More specifically the sloping wall is formed of silicon carbide tile. Air for combustion is introduced into the oven along the sides of the bed of material on the sloping wall surface and across the top of the bed into a preheat section or chamber. The gaseous reaction products developed in this preheat section or chamber, if not consumed by the oxygen in the introduced air, may be continuously withdrawn for other use or may be withdrawn and passed into subsequent combustion zones as hereinafter described. By maintaining a relatively thin, continuous bed of the solid material flowing or moving by gravity down the sloping silicon carbide surface a simple and practical method of carbonizing any carbonaceous material is provided. The burning of the volatile hydrocarbons directly above the moving bed of the solid material provides a superior means of transferring heat to this material. The hot combustion gases plus excess gases and tar vapors are passed out of this combustion zone through a suitable tunnel or passage which assists in keeping the soaking zone at a uniform temperature and such gases are then passed into an area below the silicon carbide surface or slab for passage through the same into the bed of material thereon. Means is provided for introducing additional air to raise the temperature of the gases in this latter area or main combustion zone or chamber of the oven structure. The high heat transfer properties of the silicon carbide forming the sloping Wall surfaces over which the bed of material moves provide the necessary heat for carbonizing the solid material in contact with the silicon carbide slabs.

Referring now more particularly to the drawings, the apparatus illustrated in the two embodiments shown is designed primarily for the production of low volatile char. Provision may be made in the apparatus for gas or liquifiable vapor recovery if such is desired, as will be hereinafter described. I V

' In the structure illustrated in FIGS. 1 to 7 inclusive, numeral 10 generally designates the oven structure while the numeral 12 generally designates a means for feeding the raw carbonaceous material into the oven and the numeral 14 generally designates the Water jacketed hollow heat exchanger unit by means of which the char is conveyed from the oven onto a disposal mechanism.

The oven structure 10 is here shown as of generally cubical form or construction although, of course, the. invention is not limited to this specific form, since this may be modified in the manner illustrated in FIG. 8.

The oven is of double wall construction being comprised of inner walls built of refractory brick or refractory castable materials and outer walls of insulating materials. The refractory brick or refractory castable material of the inner wall is generally designated 16 while the insulating material of the outer wall is generally designated 18. In the succeeding description of the oven structure the walls will be considered as being of one solid material for ease of reference to the'different parts of the oven structure. Accordingly, the numerals 20 and 22 designate the front and back walls respectively of the oven structure, while the numerals 24 and 26 generally designate the top and bottom walls respectively and the numeral 28 designates the side walls.

The back wall 22 slopes outwardly slightly from the top to the bottom as shown in FIG. 3, while the other upright walls, such as the front and side walls, are vertical. The interior of the oven structure is divided by a wall 30 which is in relatively close relationship with the front wall 20 of the structure and which divides the interior of the structure into an oven chamber 31 and a relatively shallow vertical channel area or products of combustion passing zone 32. The wall 30 which in effect forms the front wall of the oven chamber, is inclined slightly toward the opposite or back wall, as shown in FIG. 3, so that this wall and the inner surface of the back wall are in downwardly divergent relation for the purpose hereinafter set forth. The top wall 24 has formed therein midway between the side walls 28, an elongate opening33 which extends from the rear side of the oven chamber31 forwardly to the inner side of the wall 30. In this opening 33 is secured a sleeve 34 which extends upwardly beyond the top wall 24 and is secured to the neck portion 35 of a hopper 36.

Within the'oven chamber 31 there are positioned two sets of inclined or sloping wall slabs, one above the other. The upper set of slabs, generally designated 37, consists of the two joined and right angularly related slabs 38 which extend from the front to the back of the oven chamber 31, being joined at their front and back ends respectively to the walls 30 and 22. The two slabs 38 making up the upper set and which may be further defined as the top slabs, are joined by an apex or ridge portion 39 of refractory material. This ridge of refractory material lies directly below the center and extends longitudinally of the sleeve 34 of the hopper and the top of such ridge is in a horizontal plane in close proximity to the top of the oven chamber. Thus there are provided the relatively narrow material admission passages 40 on opposite sides of the refractory ridge portion 39.

The slabs 38 extend downwardly in divergent relation as previously stated and terminate short of the inner surfaces of the side walls of the oven chamber at approximately'the horizontal center thereof, thereby providing between the lower edges of the slabs 38 and the adjacent wall surfaces, the material feeding passages 41.

4 r in FIG. 2 and extend downwardly in convergent relation to join the floor of the oven on opposite sides of a char discharging opening 44. The bottom slabs 43 also extend from front to rear between the opposing inner surfaces of the walls 30 and 22.

The char outlet 44 is embodied in the elongate opening 45 in the bottom wall 26 of the oven structure and this opening is of a length approximately equal to the length of the oven chamber 31 between the opposing surfaces of the walls 22 and 30;

As is readily seen, the top slabs 38- are sloped to form the hereinbefore described apex which is embodied in the refractory ridge portion 39 lying beneath the feed opening so as to equally divide the flow of material to both sides of the oven chamber and in such a manner as to establish a specific bed depth of material to be carbonized. While the width of the openings or passages 41 may be adjusted according to the type of material being carbonized, it is i found that such openings may have a width of approximately 4". The height of the admission passageways 40 also determines the bed depth and means may be provided as hereinafter described for varying the height of this opening or passageway according to the size of the pieces or particles of coal being introduced into the furnace, which coal particles normally run from about 1" to 1%" in size.

The joined and downwardly sloping divergent top slabs 38 form with the adjacent walls of the chamber the two triangular shaped zones A which constitute preheat zones. The bottom slabs 43 which converge downwardly form with the adjacent oven wall surfaces two lower triangular shaped zones which are designated B and which'constitute reheat zones. It will be seen upon reference to FIGS. 2 and 4 that the arrangement of the top and bottom slabs is such as to form a central substantially diamond shaped or middle zone in the oven which is generally designated C and this central zone constitutes the main combustion zone.

The slabs 38 and 43 are composed of silicon carbide tile or silicon carbide formed in any suitable manner. This applies to both slabs with the exception, of course, of the apex portion 39 connecting the top edges of the top slabs 38. The top surface of this apex or ridge por tion for a specific length of the sloping surface of which it forms a part, depending upon the material being carbonized, must be of low heat conducting refractory material, as hereinbefore stated, to prevent the evolution, deposition and agglomeration of tars at the feed opening 33. Such an accumulation, if allowed to occur, would stop the flow of material being carbonized.

The degree of slope of the top and bottom slabs is determined or established to suit the nature, size and/ or shape of the material being carbonized so that the previously established constant feed bed depth will be maintained. As an example, and without in any way limiting the invention, it is found that in the operation of the oven for carbonizing a specific sub-bituminous coal having particle sizes ranging from one inch downward, there is required a downward slope of the slabs of approximately 28 from the horizontal.

In the operation of the apparatus for the production of low volatile char and without considering recovery of gas or liquifiable vapor, the preheat, reheat and main combustion zones are provided with suitable portsor apertures for feeding necessary air to the different zones and means is provided for recycling products of combustion from one zone to another as will be hereinafter specifically set forth in the description of the operation of the apparatus.

The heat exchanger unit, generally designated 14, is double walled or hollow to form a water chamber 46. This heat exchanger unit is in the form of a long chute having an open top of the same length as the discharge opening 45 with which it is joined and having an open bottom through which the char from the oven is expelled upon a table 47 forming a part of an extractor or discharge mechanism which is generally designated 48. The hollow chute-like heat exchanger unit is of a gradually increasing interior width from the top to the bottom thereof as shown most clearly in FIG. 2, so that the char will flow freely therethrough. Water connections 49 are provided at the top and bottom of the heat exchanger as shown to permit water to be introduced into and withdrawn therefrom. This heat exchanger unit effects the cooling of the carbon residue or char as it passes from the oven to the discharge mechanism.

The table 47 is also of a hollow construction as shown to provide a chamber 47a through which cooling water may be circulated by means of pipe connections as shown in FIG. 3 and designated 47b.

In the opening or throat leading into the heat exchanger there is positioned a dividing plate 50 which extends the length of the throat or the length of the open top of the exchanger unit and which functions to prevent massing or compacting of the carbonized material in the throat as it flows from the surfaces of the slabs 43. This dividing plate 50 projects above the surface of the bed of char and may extend to any depth into the heat exchanger unit. In FIGS. 2 and 4 the plate is shown as terminating in the upper part of the heat exchanger unit.

The char material as it approaches the two sides of the plate 50 is diverted from flow along an angular path to a vertical downward path as will be readily apparent and in the area immediately adjacent to the lower portions of the slabs 43 the char is subjected to a soaking treatment by heat concentrated in this area. In other words, the areas immediately adjacent to the lower edges of the slabs 43 and designated 43a constitute soaking areas. In these areas there is effected an exchange of heat between the particles of char to complete the carbonization of any thereof which may not have been completely carbonbized on the sloping slab.

The extractor or discharge mechanism 48 consists of the table 47 which supports the column of residue or product and an oscillating or pushing device 51 which is located centrally between the outlet of the heat exchanger and the flat table and which lies in a vertical plane passing approximately centrally through the heat exchanger.

Details of the oscillating pusher device 51 are shown in FIG. 6, where it will be seen that this device comprises a hollow or tubular shaft 52 suitably supported at its ends for rocking motion as by means of hangers 53 which may be secured to opposite ends of the heat exchanger. This shaft has extended diametrically therethrough a multiplicity of steel pins 54 which function as wiping or thrust fingers when the shaft is rocked, to sweep the char toward and off of the opposite sides of the table 47.

The tubular shaft 52 is designed to have water pass therethrough and to this end one end of the shaft is equipped with a suitable coupling 55 for the connection of a water pipe 56 therewith, the water being permitted to flow freely from the opposite end of the shaft. Thus the shaft is prevented from becoming overheated and subsequently distorted and also the cooling action of the water imparts some cooling to the productin which the shaft is imbedded. Any suitable means may be provided for rocking the shaft 52. For example, the shaft may have attached to one end a crank arm 57 coupled to an end of a link 58. The opposite end of the link may be pivotally connected as at 59 to a disc crank 60. This disc crank may be provided with a number of apertures 61 at suitable varied locations whereby the pivoted end 59 of the link may be connected as desired to eifect a change in the throw of the crank arm 57 and the degree of oscillation of the pins or fingers 54. Obviously, any suitable means may be provided for rotating the disc 60. By this means the rate of flow of material through the oven may be controlled or determined.

Any suitable means may be provided for receiving the carbonized material from the opposite sides of the table 47, the means here illustrated comprising parallel conveyors 62 suitably supported for movement longitudinally of the table, on rotary supporting elements 63 and the table is bordered on the inner and outer sides thereof by the inner and outer boards 64 and 65 respectively, which function to guide the material onto the conveyors as will be obvious.

As hereinbefore set forth, the front and back walls 22 and 30 of the oven, as well as the side walls of the heat exchanger 14, are downwardly divergent so as to provide a progressively increasing width downward to the moving bed or column of material.

Operation In putting the oven into service the oven must be preheated to a temperature of about 1800 F. with the feed hopper or bin 36, the heat exchanger 14 filled with low volatile char and beds of the char built up on the top surfaces of the top and bottom slabs. When the oven has been thus charged it is preheated and the temperature of the charge therein raised by injecting burning oil or gas into the chamber or combustion zone C through the valved air admission pipe 72 and port 73. When the desired temperature is attained the discharge mechanism 48 is started at a reduced rate and the heated char is withdrawn. The coal 66 to be carbonized in the furnace is charged into the feed bin or hopper 36 in a suitable manner as by means of a belt conveyor, drag conveyor or some other means, not shown, and permitted to flow downward by gravity onto the first sloping surfaces or top surfaces of the top slabs 38, into the preheat zones A, as the preheated char is withdrawn. Heat is provided in these zones A by conduction through the silicon carbide slabs, from the main combustion zone C which lies directly beneath the preheat zones A.

In the preheat zones A all of the moisture and some or all of the tars are evolved and exit through the openings 67 to combine with products of combustion in the zone 32. The openings 67 are controlled by suitable dampers 68. By closing the damper 68 the vapors developed in the chambers A may be removed and conveyed to a suitable condensing system for recovery by discharging the vapors through ports 670 leading out of the chambers A. Such ports are here shown closed by a suitable cap 67b but it will be obvious that by removing the caps conduits may be connected with the ports 67a for carrying off the vapors. If such recovery is not desired, then the ports 67a will be kept closed and the valve 68 opened so that the vapors may be passed into the passage 32 to be combined with the products of combustion in the chambers or zones B.

The heating rate of the material in the preheat zones A may be controlled by the introduction of air into these zones. Combustion of the gases in these preheat zones can thus be regulated as desired. The means for admitting air to the preheat zones A are here shown as comprising ports 69 in the side walls 28, with which are connected air pipes 70 and these pipes may be provided with suitable flow controlling dampers 71. The admission of air into the preheat zones is regulated or controlled in accordance with the carbonizing properties of the material being treated. Heating the material at a slow rate in the zones A gives a harder char product.

FIG. 8 illustrates on an enlarged scale a portion of the furnace structure showing one of the pipes connected therein and illustrating more clearly the control damper 71. It will be understood that each of the other pipes referred to for admitting air into the different zones will be provided with control dampers similar to the damper 71 here shown.

From the preheat zones the material advances by gravity to and through the slots or passages 41 into the main combustion zone C and onto the surfaces of the bottom silicon carbide slabs 43. The hereinbefore referred'to air pipe 72 which is connected in the port73 formed in the back wall 22, is suitably valved or damper controlled as shown and is employed for introducing air into the main combustion chamber as shown in FIGS. 2 and 3. Air introduced into this zone C facilitates combustion of the volatile tars and gases evolved therein.

The products of combustion developed in the zoneC exit through the port or opening 74 formed through the wall 30 at the front of the oven chamber, passing into the zone 32.

All of the gases collected in the zone or chamber 32 enter the reheat zone B by Way of the ports or openings 75 formed through the lower part of the'wall'30 to pro.- vide additional heat which passes through the bottom silicon carbide slabs into the bottom of the bed of material moving over the top surfaces of the bottom slabs Air admission pipes 76 open through the front wall 20 into the zone 32 for providing air for additional com.- bustion to maintain the required temperatures in the reheat zones B. These air pipes 76 are equipped with suitable dampers, not illustrated, to control the air flow therethrough.

. All of the gases from the reheat zones B pass out through the openings 77 in the back wall 22 to the pipes .78 which lead to the stack 79 to be discharged into the struction of the apparatus is such, as will be readily obvious, that where operating conditions require it the use of forced air admission may be made so as to maintain a slight positive pressure within the system. Under any condition of operation, the coal supply in the feed bin or hopper 36 and the column of the char product in the heat exchanger unit 14 provide suflicient pressure drop to minimize the flow of air or gases in or out of the feed and discharge openings. Accordingly, it will be seen that with the present apparatus or system it is not necessary to provide expensive sealed end closures at either the feed or discharge ends of the system.

FIG. 7 illustrates a furnace structure showing certain modifications of the material admission means, the structure providing the soaking zone, and the division plate extending downwardly through the char outlet.

In this FIG. 7 the hopper is generally designated 136 and the oven structure is generally designated 110, while the water jacketed hollow heat exchanger is generally designated 114.

The oven structure is here illustrated as of somewhat greater height in proportion to its width than the structure illustrated in FIG. 2 for the purpose hereinafter set forth.

In this modified construction the feeding sleeve leading from the hopper into the top part of the oven chamber 131 is designated 135 and extends into the opening 133 formed through the top wall 124 of the furnace. Within the furnace the upper inclined silicon carbide walls are designated 138, corresponding to the walls 38 of the previously described structure and these walls join at their upperor convergent portions with the refractory material apex or ridge portion 139. The lower and outer edges of the slabs 138 terminate short of the inner sides of the furnaceside walls 128 to provide the material passageways 141.

Below the slabs 138 are the lower downwardly coning to the previously described walls 43. The top edges of these walls 143 join the inner sides of the side walls 128 below the lower edges of the slabs 138 as shown so that the passageway 141 is thus formed for the transfer of char from the top surfaces of the upper slabs to the topsurfaces of the lower slabs. Thus the arrangement of slabs in FIG..8 forms the two laterally spaced preheat zones A, the lower laterally spaced reheat zones B and the central combustion zone C.

In the structure shown in FIG. 2, the area between the material inlet and the top surfaces of the ridge 39 is of fixed height. In FIG. 8 a means is provided whereby such admission area can be adjusted as to height to accommodate coal particles of different sizes. This means for adjusting or changing the height of the admission passages comprises a weir'generally designated 240 and embodying the two side plates 241 joined at their ends by the cross plate 242. The plates 241 move against the sides of the neck portion 135 and the weir can be secured in adjusted position by any suitable means as, for example, by the provision of a set screw or bolt 243 threaded into one of the plates 241 and movable in a vertical slot 244 in the adjacent neck wall, the head of the bolt being frictionally engaged against the wall of the neck when it is threaded up or tightened so as to hold the weir in position. Thus it will be seen that the bottom edges of the plates 241 can be moved from the plane of the under surface of the top wall 124 into the oven toward the ridge 139 so as to narrow the passage through which the raw material may enter.

7 In the description of the structure of FIG. 2 as given hereinabove, reference is made to a soaking zone on opposite sides of the discharge passage 44, such zone being formed by the angle between the bottom edge of each slab 43 and the bottom wall 44 of the furnace chamber. In the construction of FIG. 8 the height of the furnace chamber is increased and the soaking zone is formed by providing the short substantially vertical downward extension walls 143a at the bottom edges of the slabs 143, which extension walls are spaced apart to form the outlet throat 245. Thus it will be seen that the char material as it leaves the bottorn edges of the slabs 143 will enter the throat and will be retained for awhile in the throat to be subjected to the heat in the reheat zones B before passing down into the water jacketed heat exchanger 114.

7 There is also illustrated in FIG. 7 a division plate which extends downwardly through the throat 245 and into a substantial portion of the water jacketed heat exchanger structure.

As illustrated, the interior of the heat exchanger. structure is ofgradually increasing width from the throat 245 downwardly so that the char material can feed through the heat exchanger unit without packing to pass therefrom onto a water cooled table, not shown, corresponding to the table 47, from which the char will be discharged by the mechanism illustrated in connection with the previously described structure.

As this invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, since the scope of the invention is defined in the appended claims, and all changes that fall within the'metes and bounds of the claims, or that form their functional as well asconjointly cooperative equivalents, are therefore intended to be embraced by those claims.

I claim:

1. Apparatus for carbonizing carbonaceous raw material comprising an. oven structure, means for feeding the raw material into the top of the oven, means forming sloping downwardly diverging slabs formed through a major extent thereof of a material having a highdegree of thermal conductivity onto which said raw material is discharged from said feeding means, means forming sloping downwardly convergent slabs of a material having a high degree of thermal conductivity and lying beneath said diverging slabs and forming therewith a combustion chamber, means for discharging the raw ma terial from the lower ends of the diverging slabs onto the surfaces of the said converging slabs at the upper ends of the latter, said diverging slabs and adjacent walls of the oven structure being spaced relatively to one another and forming preheating chambers, air inlet means for said combustion chamber and air inlet means for said preheat chambers.

2. The invention according to claim 1, wherein the said material of high thermal conductivity consists of silicon carbide.

3. The invention according to claim 1, wherein the upper portions of said diverging slabs include and are joined by portions composed of low heat conducting refractory material onto which the introduced raw material first falls from the feeding means.

4. Apparatus for carbonizing carbonaceous material comprising a means forming an oven chamber having a top wall provided with a material inlet, a top pair of slabs joined to form an inverted V in the upper part of said chamber, the apex of the V forming a ridge lying beneath and in close proximity to said inlet, the slabs on each side of the ridge being formed through a minor part of their extent toward their lower edges of a low heat conducting refractory material and through the remainder and major portion of their extent being formed of material having a high degree of thermal conductivity, said slabs and adjacent walls of the oven being spaced relatively to one another and forming preheat chambers, 21 bottom pair of slabs lying directly below said top pair and joined to form an upright V, said bottom slabs being formed of material having a high degree of thermal conductivity, the said joined top slabs and the said joined bottom slabs together forming an intermediate main combustion chamber in the oven chamber, air inlet means for the combustion chamber, means for discharging material from the lower part of each top slab onto the underlying bottom slab, said slabs being sloped to a degree to cause the material to move downwardly thereon in a bed by gravity and at a predetermined rate, said oven chamber having a bottom wall outlet flanked along two opposite sides by the bottom portions of said bottom slabs, said bottom slabs forming reheat chambers with the oven chamber bottom wall and adjacent walls, means for removing gases and volatilized products from the preheat chambers, air inlet means for said preheat and reheat chambers, means for conducting products of combustion from the main combustion chamber to the reheat chambers and exhausting the products of combustion from the reheat chambers.

5. The invention according to claim 4 with a downwardly directed and downwardly expanding water jacketed heat exchanger having an upper inlet end connected with the bottom wall of the oven in alignment with said bottom wall outlet and having a lower carbonized material discharge opening.

6. The invention according to claim 5, with means below said lower discharge opening for receiving and removing the carbonized material, comprising a table spaced from the outlet of said heat exchanger, oscillatable thrust means interposed between said table and said discharge opening of the heat exchanger for moving the carbonized material laterally toward opposite sides of the table, means for actuating said oscillatable thrust means, and means adjacent to and below the said opposite sides of the table for receiving and conveying the carbonized material to a disposal area.

7. Apparatus for carbonizing carbonaceous material comprising an oven structure, means within said structure providing a first sloping wall, said sloping Wall coacting with top and side walls of the structure to provide a material preheat chamber, means for depositing material on said sloping wall for gravitational movement toward said side wall, means within said structure providing a second sloping wall extending downwardly from said side wall beneath and on an opposite slope from said first sloping wall and coacting with said side Wall and a bottom Wall of the structure to provide a reheat chamber, means forming a main combustion chamber wherein said first and second sloping walls form top and bottom walls thereof, means for discharging material from the top of said first sloping wall into said combustion chamber and onto the top of said second sloping wall, means for discharging carbonized material from the second sloping wall of the oven structure, means for conducting products of combustion from the preheat and combustion chambers into the reheat chamber, air inlet means for said chambers, and said sloping Walls being formed of material having a high degree of thermal conductivity.

8. Apparatus for carbonizing carbonaceous material comprising an oven structure having front and back Walls, top and bottom walls and side walls, said top wall having an elongate material inlet opening extending from a location adjacent to the back wall toward and terminating a substantial distance short of the front wall, means for feeding material into said inlet opening, an inner wall in the oven structure adjacent to the front wall and dividing the interior of the oven structure into an oven chamber and a products of combustion chamber, a top pair of slabs joined to form an inverted V in the upper part of said oven chamber, the apex of the V forming a ridge lying beneath and in close proximity to said material inlet and disposed in the vertical medial plane of said inlet, the slabs on each side of the ridge being formed through a minor part of their extent toward the lower edges of a low heat conducting refractory material and through the remainder and major portion of their extent being formed of material having a high degree of thermal conductivity, said slabs and adjacent Walls of the oven chamber being spaced relatively to one another and forming preheat chambers, a bottom pair of slabs lying beneath said top pair of slabs and joined to form an upright V, said bottom slabs being formed of material having a high degree of thermal conductivity, the said joined top slabs and the said joined bottom slabs together forming therebetween a main combustion chamber in the oven chamber, said inner wall and said back wall being disposed in downwardly divergent relation and said top and bottom slabs having front and back ends joined to the inner and back walls, means for discharging material from the lower part of each top slab onto the top of the underlying bottom slab and into said main combustion chamber, said slabs being sloped to a degree to cause the material to move downwardly thereon in a bed by gravity and at a predetermined rate, said oven chamber having a bottom wall outlet flanked along two opposite sides by the bottom portions of said bottom slabs whereby material gravitates from the latter slabs to and through said outlet, said bottom slabs forming reheat chambers with the oven chamber bottom wall and side walls, means for removing gases and volatilized products from the said preheat chambers through said inner wall, means for passing products of combustion from the main combustion chamber through the inner wall and into said products of combustion chamber, means for passing the products of combustion from the products of combustion chamber through the inner wall into said reheat chambers, air inlet means for said chambers, and means for exhausting the products of combustion from the reheat chambers.

9. The invention according to claim 4, wherein the said material of the slabs having a high degree of thermal conductivity is silicon carbide.

10. The invention according to claim 7, wherein the 1 1 3 said material of the slabs having a high degree of thermal conductivity is silicon carbide.

11. The invention according to claim 8, wherein the said material of the slabs having a high degree of thermal conductivity is silicon carbide.

12. Apparatus for carbonizing carbonaceous material comprising a means forming an oven chamber having a top wall provided with a material inlet, a top pair of slabs joined to form an inverted V in the upper part of said chamber, the apex of the V forming a ridge lying beneath and in close proximity to said inlet, the slabs on each side of the ridge being formed through a minor part of their extent toward their lower edges of a low heat conducting refractory material and through the reinainder and major portion of their extent being formed of material having a high degree of thermal conductivity, said slabs forming preheat chambers with adjacent walls of the oven chamber, a weir means in said inlet and adjustable into the oven chamber toward said ridge tovary the height of the space through which the material passes between the inlet and the ridge, means for securing the weir in vertically adjusted position, a bottom pair of slabs lying below said top pair and joined to human upright V, said bottom slabs being formed of material having a high degree of thermal conductivity, the said joined inverted V forming top slabs and the said joined upright'V forming bottom slabs being disposed one above the other with the concavities of the Vs opposed and forming a main combustion chamber in the oven chamber, meansfor discharging material from the lower part of each top slab onto the underlying bottom slab, said slabs being sloped to a degree to cause the material to move downwardly thereon in a bed by gravity and at a predetermined rate, said oven chamber having a bottom wall outlet flanked along two opposite sides by the bottom portions of said bottom slabs, said bottom slabs forming reheat chambers with the oven chamber bottom wall and adjacent walls, air admitting means for said combustion, preheat, and reheat chambers, means for removing gases and volatilized products from the preheat chambers, means for conducting products of combustion from the main combustion chamber to the reheat chambers and exhausting the products of combustion from the reheat chambers.

13. Apparatus for carbonizing carbonaceous material comprising a means forming an oven chamber having a top wall provided with a material inlet, a top pair of slabs joined to form an inverted V in the upper part of said chamber, the apex of the V forming a ridge lying beneath and in close proximity to said inlet, the slabs on each side of the ridge being formed through a minor part of their extent toward their lower edges of a .low heat conducting refractory material and through the resaid oven chamber'having a bottom wall outlet, said mainder and major portion of their extent being formed of material having a high degree of thermal conductivity, said slabs forming preheat chambers with adjacent walls of the oven chamber, a bottom pair of slabs lying below said top pair and joined to form an upright V, said bot-; tom slats being formed of material having a high degree of thermal conductivity, the said joined inverted V forming top slabs and the said joined upright V forming bottom slabs being disposed one above the other with the concavities of the Vs opposed and forming a main com bustion chamber in the oven chamber, means' for dis charging material from the lower part of each top slab onto the underlying, bottom slab, said slabs being sloped to a degree to, cause the material to move downwardly thereon in a bed by gravity and at a predetermined rate,

bottom slabs beingjoined along their bottom portions to low vertical walls extending down and joined to the 1 bottom wall along opposite sides of said outlet to form a soaking throat wherein completion of carbonization will be effected of any char incompletely carbonized on the adjacent slabs, said bottom slabs and vertical walls forming reheat chambers with the oven chamber bottom wall and adjacent walls, means for removing gases and volatilized products from the preheat chambers, means for conducting products of combustion from the main combustion chamber to the reheat chambers and exhausting the products of combustion from the reheat chambers, and air admission means for the combustion, preheat and reheat chambers.

References Cited by the Examiner UNITED STATES PATENTS Examiners. 

1. APPARATUS FOR CARBONIZING CARBONACEOUS RAW MATERIAL COMPRISING AN OVER STRUCTURE, MEANS FOR FEEDING THE RAW MATERIAL INTO THE TOP OF THE OVEN, MEANS FORMING SLOPINGS DOWNWARDLY DIVERGING SLABS FORMED THROUGH A MAJOR EXTENT THEREOF OF A MATERIAL HAVING A HIGH DEGREE OF THERMAL CONDUCTIVITY ONTO WHICH SAID RAW MATERIAL IS DISCHARGE FROM SAID FEEDING MEANS, MEANS FORMING SLOPING DOWNWARDLY CONVERGENT SLABS OF A MATERIAL HAVING A HIGH DEGREE OF THERMAL CONDUCTIVITY AND LYING BENEATH SAID DIVERGING SLABS AND FORMING THEREWITH A 